Jakub Kicinski db314398f6 Merge branch 'net-bridge-mcast-support-exponential-field-encoding'
Ujjal Roy says:

====================
net: bridge: mcast: support exponential field encoding

Description:
This series addresses a mismatch in how multicast query
intervals and response codes are handled across IPv4 (IGMPv3)
and IPv6 (MLDv2). While decoding logic currently exists,
the corresponding encoding logic is missing during query
packet generation. This leads to incorrect intervals being
transmitted when values exceed their linear thresholds.

The patches introduce a unified floating-point encoding
approach based on RFC3376 and RFC3810, ensuring that large
intervals are correctly represented in QQIC and MRC fields
using the exponent-mantissa format.

Key Changes:
* ipv4: igmp: get rid of IGMPV3_{QQIC,MRC} and simplify calculation
  Removes legacy macros in favor of a cleaner, unified
  calculation for retrieving intervals from encoded fields,
  improving code maintainability.

* ipv6: mld: rename mldv2_mrc() and add mldv2_qqi()
  Standardizes MLDv2 terminology by renaming mldv2_mrc()
  to mldv2_mrd() (Maximum Response Delay) and introducing
  a new API mldv2_qqi for QQI calculation, improving code
  readability.

* ipv4: igmp: encode multicast exponential fields
  Introduces the logic to dynamically calculate the exponent
  and mantissa using bit-scan (fls). This ensures QQIC and
  MRC fields (8-bit) are properly encoded when transmitting
  query packets with intervals that exceed their respective
  linear threshold value of 128 (for QQI/MRT).

* ipv6: mld: encode multicast exponential fields
  Applies similar encoding logic for MLDv2. This ensures
  QQIC (8-bit) and MRC (16-bit) fields are properly encoded
  when transmitting query packets with intervals that exceed
  their respective linear thresholds (128 for QQI; 32768
  for MRD).

* selftests: net: bridge: add MRC and QQIC field encoding tests
  Updates bridge selftests to validate both linear and non-linear
  (exponential) encoding for MRC and QQIC fields, ensuring
  protocol compliance across IGMPv3 and MLDv2.

Impact:
These changes ensure that multicast queriers and listeners
stay synchronized on timing intervals, preventing protocol
timeouts or premature group membership expiration caused
by incorrectly formatted packet headers.
====================

Link: https://patch.msgid.link/20260502131907.987-1-royujjal@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-04 19:09:43 -07:00
2026-01-26 19:07:09 -08:00
2026-04-26 14:19:00 -07:00

Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer - Getting started with kernel development
* Academic Researcher - Studying kernel internals and architecture
* Security Expert - Hardening and vulnerability analysis
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* System Administrator - Configuring and troubleshooting
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* Hardware Vendor - Writing drivers for new hardware
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* AI Coding Assistant - LLMs and AI-powered development tools


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
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* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
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---------------

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Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
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Hardware Vendor
---------------

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* Driver API Guide: Documentation/driver-api/index.rst
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* Device Drivers: Documentation/driver-api/infrastructure.rst
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* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


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=========================

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